Responses of Native and Non-native Bark and Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) to Different Chemical Attractants: Insights From the USDA Forest Service Early Detection and Rapid Response Program Data Analysis

More than 60 non-native bark and ambrosia beetle species (Coleoptera: Curculionidae: Scolytinae) are established in North America and several have had severe negative impacts on ecosystems. Non-native scolytines can introduce fungi which may cause vascular wilts and compete with native fungi and lead to reductions in native species through host reduction. The Early Detection Rapid Response (EDRR) program was created by the USDA Forest Service in 2007 to detect non-native bark and ambrosia beetles and provide a baseline for tracking populations over time. This program has led to new collection records and increased communication among agencies to delimit non-native scolytine populations and perform appropriate management. Although insect responses to different lure types vary, it is unknown how different lures compare in attracting bark and ambrosia beetles. Our goal was to examine how lure combinations used in the EDRR program affect captures of bark and ambrosia beetle communities and to determine the most effective combination of lures for targeting non-native scolytines. The highest proportion of non-native scolytines was captured with ethanol, as was the greatest total number of species, and the most diverse beetle community. Traps with Ips (Coleoptera: Curculionidae) lures captured the highest proportion of native scolytines but the lowest total number of total species and was also the least diverse. Communities of scolytines differed significantly among lures, states, and years. While ethanol is an appropriate lure for generalist trapping and targeting a wide range of non-native bark and ambrosia beetles, more targeted lures are needed for monitoring certain species of non-natives.